Issue |
A&A
Volume 458, Number 2, November I 2006
|
|
---|---|---|
Page(s) | L13 - L16 | |
Section | Letters | |
DOI | https://doi.org/10.1051/0004-6361:20066093 | |
Published online | 13 September 2006 |
Letter to the Editor
Stellar X-ray heating of planet atmospheres
1
INAF - Osservatorio Astronomico di Cagliari, Strada 54, Loc. Poggio dei Pini, 09012 Capoterra (CA), Italy e-mail: ccp@ca.astro.it
2
INAF - Osservatorio Astronomico di Palermo, Piazza Parlamento 1, 90134 Palermo, Italy e-mail: ciarave@astropa.unipa.it, giusi@astropa.unipa.it
Received:
24
July
2006
Accepted:
28
August
2006
Aims.To investigate the effects of the stellar X-ray irradiation on planet atmospheres, we study the X-ray transfer and energy deposition in a hydrogen rich gas.
Methods.We construct an accurate X-ray transfer model taking both photoionization and Compton scattering into account; the electron energy deposition is followed by tracking the discrete exchange processes between electrons and the gas mixture.
Results.Exospheric heating rates are derived as functions of the pressure in model atmospheres using a wide range of X-ray luminosity, spectral hardness representative of different stellar ages, and distances from the parent star. The computed heating rates suggest that X-ray irradiation might be an important heating source in planetary exospheres even at large distances from the parent star.
Key words: planetary systems / X-rays: stars / radiative transfer
© ESO, 2006
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.